This invention relates to an overload protection system for a counterbalanced lift truck and in particular to an overload protection system which is responsive to the tilting moment acting on the truck and inhibits further raising of the load support or tilting the mast further forward when the tilting moment is excessive, thereby preventing the operator from increasing the danger of overturning the truck during material handling operations.
Several systems are known for preventing excessive forward overturning, or tilting moment in a counterbalanced lift truck. While known systems have considerable utility, none has actually proven fully effective because of such drawbacks as high cost, unnecessary space requirement, difficulty to maintain in efficient operating condition, not being fully automatic, not being tamperproof, not being fail-safe, or being unstable and providing false response in operation.